The snapshot manager shows no snapshots available. After the revert it is greyed out.

I do have a number of delta's that look like they are the snapshots.

Machine-000001.vmdk
Machine-000001-delta.vmdk
Machine-000002.vmdk
Machine-000002-delta.vmdk
Machine-000003.vmdk
Machine-000003-delta.vmdk
Machine-000004.vmdk
Machine-000004-delta.vmdk

I have assumed that 000003 and 000004 are the snapshots I need to apply and 000001 and 000002 are the reverted originals.

I have tried to do a "Remove from Inventory" and add it back in again....

BTW Why is there no warning to revert?

Well... after varied success....

I have my VM working again...

My process involved working out which disk-delta's belonged to the actual machine state that I had to recover.

Without a valid [machine]-snapshot.vmsn I had to recreate one of these. I renamed my old 00000X disks to old (to avoid getting 00005 and 000006)

Once I have renamed them I renamed and mounted the original, unmodified vmdk's (C and D drive)
(I had to boot into windows becuase I could not logon to windows later when the snapshots were applied, not sure why? it would logon then logoff due to something corrupted)

Once I started the VM, I shut it down (Changing nothing) I then used the snapshot manager to create a snapshot. (This got me my vmsd)

I then copied my old 000002 and 000004 over the newly created snapshots.

**When I restarted I did get some CHKDSK problems and a minor registry issue but the server recovery was successful. I was happy to loose a few files to CHKDSK then all of the data that had changed***

The server was a SQL and Biztalk server.

**I hope that they add an "Are you sure" option to reverting a snapshot**